MOF‐Derived Fe7S8 Nanoparticles/N‐Doped Carbon Nanofibers as an Ultra‐Stable Anode for Sodium‐Ion Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 17; no. 38
• Main Authors: Wang, Yu, Wen, Zi, Wang, Chang Chun, Yang, Chun Cheng, Jiang, Qing
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2021
• Subjects: Anodes; Carbon fibers; cycling stability; Decay rate; Electrochemical analysis; Electrode materials; Energy storage; Fe 7S 8 nanoparticles; metal‐organic framework; Nanofibers; Nanoparticles; Nanotechnology; N‐doped carbon nanofibers; Rechargeable batteries; Sodium-ion batteries; sodium‐ion batteries anodes; Storage systems
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202102349

Sodium‐ion batteries (SIBs) have aroused wide concern due to their potential applications in large‐scale energy‐storage systems. In this work, a hybrid of Fe7S8 nanoparticles/N‐doped carbon nanofibers (Fe7S8/N‐CNFs) is designed and synthesized via electrospinning. As an anode for SIBs, Fe7S8/N‐CNFs exhibit a high reversible capacity of 649.9 mAh g−1 at 0.2 A g−1 after 100 cycles, and superior cycling stability for 2000 cycles at 1 A g−1 with only 0.00302% capacity decay per cycle. Such excellent performance originates from: i) Fe7S8 nanoparticles (average diameter of 17 nm), which shorten the Na+ diffusion distance; ii) the unique 3D N‐CNFs, which enhance the conductivity, alleviate the self‐agglomeration and large volume change of Fe7S8 nanoparticles, and offer numerous active sites for Na+ adsorption and paths for electrolyte diffusion. The fascinating structure and superior electrochemical properties of Fe7S8/N‐CNFs shed light on developing high‐performance SIBs anode materials. A hybrid of metal‐organic framework‐derived Fe7S8 nanoparticles/N‐doped carbon nanofibers (Fe7S8/N‐CNFs) is constructed via electrospinning and sulfuration. Owing to the synergistic effect of Fe7S8 nanoparticles and carbon network, Fe7S8/N‐CNFs exhibit superior cycling stability for 2000 cycles at 1 A g−1 with only 0.00302% decay per cycle as an anode material in sodium‐ion batteries.